Mercurial > hg > nginx
view src/core/ngx_regex.c @ 7883:41f4bd4c51f1
Disabled control characters and space in header names.
Control characters (0x00-0x1f, 0x7f), space, and colon were never allowed in
header names. The only somewhat valid use is header continuation which nginx
never supported and which is explicitly obsolete by RFC 7230.
Previously, such headers were considered invalid and were ignored by default
(as per ignore_invalid_headers directive). With this change, such headers
are unconditionally rejected.
It is expected to make nginx more resilient to various attacks, in particular,
with ignore_invalid_headers switched off (which is inherently unsecure, though
nevertheless sometimes used in the wild).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 28 Jun 2021 18:01:18 +0300 |
parents | f684178faec9 |
children | 2ca57257252d |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> typedef struct { ngx_flag_t pcre_jit; } ngx_regex_conf_t; static void * ngx_libc_cdecl ngx_regex_malloc(size_t size); static void ngx_libc_cdecl ngx_regex_free(void *p); #if (NGX_HAVE_PCRE_JIT) static void ngx_pcre_free_studies(void *data); #endif static ngx_int_t ngx_regex_module_init(ngx_cycle_t *cycle); static void *ngx_regex_create_conf(ngx_cycle_t *cycle); static char *ngx_regex_init_conf(ngx_cycle_t *cycle, void *conf); static char *ngx_regex_pcre_jit(ngx_conf_t *cf, void *post, void *data); static ngx_conf_post_t ngx_regex_pcre_jit_post = { ngx_regex_pcre_jit }; static ngx_command_t ngx_regex_commands[] = { { ngx_string("pcre_jit"), NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, 0, offsetof(ngx_regex_conf_t, pcre_jit), &ngx_regex_pcre_jit_post }, ngx_null_command }; static ngx_core_module_t ngx_regex_module_ctx = { ngx_string("regex"), ngx_regex_create_conf, ngx_regex_init_conf }; ngx_module_t ngx_regex_module = { NGX_MODULE_V1, &ngx_regex_module_ctx, /* module context */ ngx_regex_commands, /* module directives */ NGX_CORE_MODULE, /* module type */ NULL, /* init master */ ngx_regex_module_init, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_pool_t *ngx_pcre_pool; static ngx_list_t *ngx_pcre_studies; void ngx_regex_init(void) { pcre_malloc = ngx_regex_malloc; pcre_free = ngx_regex_free; } static ngx_inline void ngx_regex_malloc_init(ngx_pool_t *pool) { ngx_pcre_pool = pool; } static ngx_inline void ngx_regex_malloc_done(void) { ngx_pcre_pool = NULL; } ngx_int_t ngx_regex_compile(ngx_regex_compile_t *rc) { int n, erroff; char *p; pcre *re; const char *errstr; ngx_regex_elt_t *elt; ngx_regex_malloc_init(rc->pool); re = pcre_compile((const char *) rc->pattern.data, (int) rc->options, &errstr, &erroff, NULL); /* ensure that there is no current pool */ ngx_regex_malloc_done(); if (re == NULL) { if ((size_t) erroff == rc->pattern.len) { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "pcre_compile() failed: %s in \"%V\"", errstr, &rc->pattern) - rc->err.data; } else { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "pcre_compile() failed: %s in \"%V\" at \"%s\"", errstr, &rc->pattern, rc->pattern.data + erroff) - rc->err.data; } return NGX_ERROR; } rc->regex = ngx_pcalloc(rc->pool, sizeof(ngx_regex_t)); if (rc->regex == NULL) { goto nomem; } rc->regex->code = re; /* do not study at runtime */ if (ngx_pcre_studies != NULL) { elt = ngx_list_push(ngx_pcre_studies); if (elt == NULL) { goto nomem; } elt->regex = rc->regex; elt->name = rc->pattern.data; } n = pcre_fullinfo(re, NULL, PCRE_INFO_CAPTURECOUNT, &rc->captures); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_CAPTURECOUNT) failed: %d"; goto failed; } if (rc->captures == 0) { return NGX_OK; } n = pcre_fullinfo(re, NULL, PCRE_INFO_NAMECOUNT, &rc->named_captures); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_NAMECOUNT) failed: %d"; goto failed; } if (rc->named_captures == 0) { return NGX_OK; } n = pcre_fullinfo(re, NULL, PCRE_INFO_NAMEENTRYSIZE, &rc->name_size); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_NAMEENTRYSIZE) failed: %d"; goto failed; } n = pcre_fullinfo(re, NULL, PCRE_INFO_NAMETABLE, &rc->names); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_NAMETABLE) failed: %d"; goto failed; } return NGX_OK; failed: rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, p, &rc->pattern, n) - rc->err.data; return NGX_ERROR; nomem: rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "regex \"%V\" compilation failed: no memory", &rc->pattern) - rc->err.data; return NGX_ERROR; } ngx_int_t ngx_regex_exec_array(ngx_array_t *a, ngx_str_t *s, ngx_log_t *log) { ngx_int_t n; ngx_uint_t i; ngx_regex_elt_t *re; re = a->elts; for (i = 0; i < a->nelts; i++) { n = ngx_regex_exec(re[i].regex, s, NULL, 0); if (n == NGX_REGEX_NO_MATCHED) { continue; } if (n < 0) { ngx_log_error(NGX_LOG_ALERT, log, 0, ngx_regex_exec_n " failed: %i on \"%V\" using \"%s\"", n, s, re[i].name); return NGX_ERROR; } /* match */ return NGX_OK; } return NGX_DECLINED; } static void * ngx_libc_cdecl ngx_regex_malloc(size_t size) { ngx_pool_t *pool; pool = ngx_pcre_pool; if (pool) { return ngx_palloc(pool, size); } return NULL; } static void ngx_libc_cdecl ngx_regex_free(void *p) { return; } #if (NGX_HAVE_PCRE_JIT) static void ngx_pcre_free_studies(void *data) { ngx_list_t *studies = data; ngx_uint_t i; ngx_list_part_t *part; ngx_regex_elt_t *elts; part = &studies->part; elts = part->elts; for (i = 0; /* void */ ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; elts = part->elts; i = 0; } if (elts[i].regex->extra != NULL) { pcre_free_study(elts[i].regex->extra); } } } #endif static ngx_int_t ngx_regex_module_init(ngx_cycle_t *cycle) { int opt; const char *errstr; ngx_uint_t i; ngx_list_part_t *part; ngx_regex_elt_t *elts; opt = 0; #if (NGX_HAVE_PCRE_JIT) { ngx_regex_conf_t *rcf; ngx_pool_cleanup_t *cln; rcf = (ngx_regex_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_regex_module); if (rcf->pcre_jit) { opt = PCRE_STUDY_JIT_COMPILE; /* * The PCRE JIT compiler uses mmap for its executable codes, so we * have to explicitly call the pcre_free_study() function to free * this memory. */ cln = ngx_pool_cleanup_add(cycle->pool, 0); if (cln == NULL) { return NGX_ERROR; } cln->handler = ngx_pcre_free_studies; cln->data = ngx_pcre_studies; } } #endif ngx_regex_malloc_init(cycle->pool); part = &ngx_pcre_studies->part; elts = part->elts; for (i = 0; /* void */ ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; elts = part->elts; i = 0; } elts[i].regex->extra = pcre_study(elts[i].regex->code, opt, &errstr); if (errstr != NULL) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "pcre_study() failed: %s in \"%s\"", errstr, elts[i].name); } #if (NGX_HAVE_PCRE_JIT) if (opt & PCRE_STUDY_JIT_COMPILE) { int jit, n; jit = 0; n = pcre_fullinfo(elts[i].regex->code, elts[i].regex->extra, PCRE_INFO_JIT, &jit); if (n != 0 || jit != 1) { ngx_log_error(NGX_LOG_INFO, cycle->log, 0, "JIT compiler does not support pattern: \"%s\"", elts[i].name); } } #endif } ngx_regex_malloc_done(); ngx_pcre_studies = NULL; return NGX_OK; } static void * ngx_regex_create_conf(ngx_cycle_t *cycle) { ngx_regex_conf_t *rcf; rcf = ngx_pcalloc(cycle->pool, sizeof(ngx_regex_conf_t)); if (rcf == NULL) { return NULL; } rcf->pcre_jit = NGX_CONF_UNSET; ngx_pcre_studies = ngx_list_create(cycle->pool, 8, sizeof(ngx_regex_elt_t)); if (ngx_pcre_studies == NULL) { return NULL; } return rcf; } static char * ngx_regex_init_conf(ngx_cycle_t *cycle, void *conf) { ngx_regex_conf_t *rcf = conf; ngx_conf_init_value(rcf->pcre_jit, 0); return NGX_CONF_OK; } static char * ngx_regex_pcre_jit(ngx_conf_t *cf, void *post, void *data) { ngx_flag_t *fp = data; if (*fp == 0) { return NGX_CONF_OK; } #if (NGX_HAVE_PCRE_JIT) { int jit, r; jit = 0; r = pcre_config(PCRE_CONFIG_JIT, &jit); if (r != 0 || jit != 1) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "PCRE library does not support JIT"); *fp = 0; } } #else ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "nginx was built without PCRE JIT support"); *fp = 0; #endif return NGX_CONF_OK; }